import java.util.Scanner;

public class Factorial {
	public static void main(String[] args) {
int mark,i,sum=1;
		  Scanner sc=new Scanner(System.in);
		  
             System.out.print(" Input mark :  ");
		  
              mark =sc.nextInt();
		  
              for(i=1;i<=mark;i++)
		   {
			 
                 sum*=i; 
		  
                  }
		 
    System.out.println("n! = " + sum);
	
}
}	
